due to the change from the Julian to the Gregorian calendar in 1582, English letter writers often used two dates on their letters, a practice known as dual dating?
Question 1: While ________ and presumably Sosigenes were aware of the discrepancy, although not of its correct value, it was evidently felt to be of little importance at the time of the Julian reform.
Question 2: While the Julian reform applied originally to the Roman calendar, many of the other calendars then used in the Roman Empire were aligned with the reformed calendar under ________.
Question 3: The Julian calendar, a reform of the Roman calendar, was introduced by ________ in 46 BC, and came into force in 45 BC (709 ab urbe condita).
Question 6: However, most of those countries began their numbered year on 25 December (the Nativity of Jesus), 25 March (the Incarnation of Jesus), or even ________, as in France (see the Liturgical year article for more details).
Question 10: The Julian calendar remained in use into the 20th century in some countries as a civil ________, but thirteen days have been excised to make the date the same as in other countries.